Oil purification process



J. B. ROGERSON OIL PURIFICATION PROCESS Filed March 21,'1938 Mardn 19, 1940.

Patented Mar. 19, 1940 untreu stares rarest orifice 2,194,269 on. PURIFICATION PROCESS f John B. Rogerson, El Dorado, Ark. 4 Applietion March 21, 1938, Serial No. 19%,223 1 claim. (ci. 19t- 4) i 'I'his invention relates to an oil purification process, and with regard to certain more specic features, to a'process of rectifying crude petroleum oil or fractions thereof by removing salts,

acids, and other impurities (or any of them) occurring either naturally or otherwise in the crude oil or crude oil fractions. i

Among the several objects of the invention may be noted (1) the provision of a process whereby the salts are reformed to a more crystalline state so that they may be removed by ltration; (2) the provision of a process of the class described whereby certain constituents due to chemical reactions are reformed to salts and soaps (or either of them) so that the salts or soaps may be removed by filtration; and (3) the provision of a process of the class described whereby said salts or soaps (or both) are removed by filtration. Other objects will bein part obvious and in part pointed out hereinafter:

The invention accordingly comprises the steps and sequence of steps, and features of synthesis, which will be exemplied in the process hereinafter described, and the scope of the application of which will be indicated in the following claim.

In the accompanying drawing, in which is illustrated one of various possible embodiments In the refining process and under the heat of y distillation these salts precipitate in the tubes and vessels of the distillation equipment, thus necessitating frequent and costly cleaning and replacement of distillation equipment parts. Furthermore, under certain conditions these salts disintegrate, forming reaction products which in turn severely corrode the equipment to cause further costly replacements. Many crude oils also contain hydrogen sulphide or other chemically reacting constituents which likewise are corrosive and otherwise objectionable.

The rst object above enumerated is accomof the invention, the single figure diagrammatcomplished by treating the corrosive-or otherwise objectionable oil with a suitable chemical suchI as lime, caustic soda, or other agent for neutralizing acid. The oil is then passed through a heating process, such as described under the procedure for carrying out the rst ob'- ject, and the water and low-boiling fractions, if present, are removed. 'Ihe salts, soaps, and the like either originally in the crude oil or which are formed by chemical reaction with the neutralization agent are removed by iltration.

The third object of the invention is accom- `plished by passing the oil, which is now free of water (dehydrated), and free of low-boiling constituents, through a lter either of the vacuum or pressure type, wherein the lterable salts, soaps, or other objectionable materials, are removed, and from which an oil is obtained which is substantially clean and dry.

Referring now more particularly to the drawing, vthe crude oil to be rectified is introduced into the system through pipe I. This oil may be acid or salty or both. If hydrogen sulphide or other objectionable chemically reacting constituents are to be removed, a suitable neutralizing agent, such as lime, caustic soda, or the like, is introduced into pipe l through pipe 2.- The oil and the chemicals then intimately mix and pass through pipes 3 and 4 to a rst heat exchanger E, thence through pipes 5 and 6 toa second heat exchanger A. s

It is to be noted that a system of valves l, 8

and S may be adjusted so that only a portion of the oil charge is passed through exchanger E,'

if desired, in order to` control the temperature of the oil (which later passes to a lter press)'so that it is best suited for iilter press operation.v

From the second heat exchanger A the oil,

which has already absorbed considerable preheat t from the exchangers E and A, passes through pipe y I0 into the coils l l located in the heater B. The

heater B is here represented as being a pipe still of conventional type. Back pressure (which is super-atmospheric) `is held on the heating assemhly bymeans of a tail Valve I2 to prevent excessive deposition of salt or chemicals in the heating equipment. The heated oil is then discharged through pipe I 3 into vessel C Which is on the reduced pressure side of the system.

Water and loW-boiling-temperature constitu= ents, if present in the oil, are vaporized in vessel C and discharged through pipe M into the fractionating equipment G and condensing equipment H. To assist vapcrization in tower C, steam or its equivalent, preferablysuperheated, is injected through pipe I5 into Vessel C.

The dehydrated oil is Withdrawn from Vessel C by means of pump D and passed through pipe l 6 to the first heat .exchanger E, Where itis cooled to a suitable filtration temperature (as above indicated) and introduced through pipe to the lter F. The lter shown is a.V suitable continwl ous, precoat vacuum or pressure lter Which permits of a continuous flow of oil. Certain salts,

chemicals, ch emicalreaction products from theV oil, and a certain amount of lter material are discharged together through pipe l 8 into sump J.

The rectified, clean and dry oil leaves the lter through pipe I9 and is transferred to the second heat exchanger A by means of pipe 2i). From .the exchanger A the oil passes through pipes 2l and 22 to the surge drum receiver K from which it is Withdrawn by pump L and discharged through pipe 25 to the distillation equipment for further and ordinary refining or to sto-rage. Valves 23, 24 and 25 may be adjusted so that a portion or all of the oil from` the filter F may bypass the second heat exchanger A if so desired.

In View of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As many changes could be made in carrying out the above processes without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense..`

I claim: y

The continuous process of treating salt-i.. pregnated crude oil comprising heating said oil under super-atmospheric pressure adapted to prevent excessivedeposition of sait in the necessary heating equipment, releasing said pressure to a lower one `and hea-ting the oil under the lower pressure to a degree adapted to .effect vapcrization ofl Water and loW-boiling-point constituents whereby the salt is placed in a more crystallized state,` and ltering the unvaporized portions to remove the crystallized salt.

JOI-IN B. ROGERSON. 

